Conventionally, there is proposed a map display device that displays three-dimensional map images (e.g., see patent document 1). The map display device disclosed in patent document 1 uses an automatically configured initial value or a user-specified value to calculate the most recent viewpoint altitude. The viewpoint altitude indicates an altitude resulting from adding an additional altitude to the current altitude. The additional altitude indicates a difference between the current altitude and a previously calculated altitude. The map display device adds the additional altitude to the most recent viewpoint altitude to determine a viewpoint altitude for rendering a three-dimensional map image. The map display device renders a three-dimensional map image using the determined viewpoint altitude.                Patent document 1: JP-3250554 B2 (JP-2001-27532 A)        
The above-mentioned conventional technology can extend the range of displaying a three-dimensional map image by, for example, changing the map image scale or increasing the viewpoint altitude. In this case, however, display contents near a subject vehicle where the map display device is mounted are also reduced. It is impossible to prevent the display contents near the subject vehicle from being reduced while extending the display range.